DESCRIPTION (Applicant's Abstract): The long-term objective is this study is to determine whether standard hormone replacement therapy is safe for menopausal women with epilepsy. The benefits of hormone replacement therapy for menopausal women are becoming widely appreciated. It is expected that hormone replacement therapy will be increasingly prescribed in a portion of the American population that is also increasing in number. Therefore, the safety of hormone replacement therapy in the settings of specific illnesses must be clear. Estrogen has neuroactive properties that are largely beneficial, that is, it can improve cerebral blood flow, promote axonal sprouting and helps to prevent protein precipitation in the brain pathognomonic of Alzheimer's Disease. However, estrogen and progesterone also have effects on increasing brain excitability which have been demonstrated in animal models of epilepsy, In these settings, estrogen, and to a lesser extent, progesterone, have been proconvulsant. Therefore, an adverse effect of hormone replacement on patients with epilepsy may be postulated. The question posed in this study is, does hormone replacement therapy adversely affect seizures or is it safe for menopausal women with epilepsy? To answer this question, women with epilepsy who are menopausal for at least one year (1 year without menses) and are medically cleared to take hormone replacement therapy will be enrolled. They will be followed for a three month period while taking their usual antiepileptic medications without dosage change. During this prospective baseline period, seizure frequency will be documented. After three months, subjects will be randomized to take either placebo or one of two doses of standard hormone replacement therapy. The hormone replacement therapy used will be Prempro at doses of 1) 0.625 mg conjugated equine estrogens with 2.5 mg medroxyprogesterone and 2) 1.25 mg conjugated equine estrogens with 5 mg medroxyprogesterone. The investigators and the subjects will be blinded as to the study medication given. The subjects will then be followed for a three month prospective treatment phase and again seizure frequency will be documented. Subjects will be monitored for safety concerns regarding hormone replacement therapy and seizure frequency. The outcome of this study will be determined by comparing seizure frequency in the baseline phase with the treated phase between placebo and hormone treated groups.